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Finding the Fourth Proportional to 645.40, 890.65 and 350.67

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Solution

The fourth proportional to 645.40, 890.65 and 350.67 is: 483.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.40 : 890.65 = 350.67 : x
  2. Step 2: Convert to fraction form
    645.40/890.65 = 350.67/x
  3. Step 3: Cross multiply
    645.40x = 890.65 × 350.67
  4. Step 4: Simplify right side
    645.40x = 312,324.24
  5. Step 5: Solve for x
    x = 312,324.24/645.40
  6. Step 6: Final answer
    x = 483.92

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.